Thunbergia alata
black-eyed Susan
T. alata is a moderately fast-growing, evergreen, perennial twining climber, often grown as an annual, to 2.5m tall with heart-shaped to oval toothed leaves. Flat, salver-shaped, orange to yellow flowers with dark brown centres are borne from summer to early autumn
Size
Ultimate height
1.5–2.5 metresTime to ultimate height
1–2 yearsUltimate spread
0.5–1 metresGrowing conditions
Moisture
Moist but well–drained, Well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Orange Yellow | Green | ||
| Autumn | Orange Yellow | Green | ||
| Winter |
Position
- Full sun
Aspect
South–facing or West–facing
Exposure
Sheltered Hardiness
H2Botanical details
- Family
- Acanthaceae
- Native to the UK
- No
- Foliage
- Deciduous
- Habit
- Climbing
- Genus
Thunbergia can be annuals or perennials, often twining climbers, with simple opposite leaves and trumpet-shaped or salver-shaped flowers borne singly in leaf axils, or in racemes, in summer
- Name status
Correct
- Plant range
- Tropical Africa
How to grow
Cultivation
Grow in well-drained soil in full sun with a support for the plant to climb
Propagation
Propagate by seed or if grown under glass, propagate by semi-ripe cuttings in late summer
Suggested planting locations and garden types
- Cottage and informal garden
- Patio and container plants
- City and courtyard gardens
- Flower borders and beds
Pruning
No pruning required outdoors. If grown under glass, pruning group 11
Pests
Aphids may cause problems and various pests such as glasshouse red spider mite, glasshouse whitefly and scale insects may be a problem under glass
Diseases
May be affected by powdery mildews
Get involved
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.